The Cahaba Basin is a geologic area of central Alabama developed for coal and coalbed methane (CBM) production. Centered in eastern Bibb and southwestern Shelby Counties, the basin is significantly smaller in area and production than the larger Black Warrior Basin in Tuscaloosa and western Jefferson Counties to the northwest. The coalbed methane is produced from the Gurnee Field of the Pottsville Coal Interval. Coalbed gas production has been continuous since at least 1990 and annual gas production has increased from 344,875 Mcf in 1990 to 3,154, 554 Mcf through October 2007.